It is known that unsaturated carboxylic acids may be reduced to the corresponding alcohol. However, the reducing catalysts which have heretofore been employed are not selective in the hydrogenation process, and thus the reductive process usually results in eliminating the retention of the unsaturation in the carbon chain. The compound which is obtained is therefore a saturated alcohol. This is true when utilizing catalysts such as a mixture of copper and chromium oxide, rhenium catalysts which may be used in either a supported or unsupported state or which may also contain a noble metal of Group VIII of the Periodic Table, such as platinum, palladium or ruthenium.
In many instances, it is desired to retain the unsaturation of the carbon chain when obtaining either alcohols or esters of the starting unsaturated acid. As will hereinafter be shown in greater detail, it has now been discovered that by utilizing a novel catalytic composition of matter, it is possible to effect a reductive reaction in which the double bonds present in the unsaturated carboxylic acid will be retained.